Method for producing aromatic diamine derivative

ABSTRACT

The invention provides a method for efficiently producing an aromatic diamine derivative represented by formula (3) at high yield, the method including reacting an aromatic amide represented by formula (1) with an aromatic halide represented by formula (2): 
                         
(wherein each of Ar, Ar 1  and Ar 2  represents a substituted or unsubstituted aryl group or heteroaryl group; Ar 3  represents a substituted or unsubstituted arylene group or heteroarylene group; and X represents a halogen atom).

CLAIM OF PRIORITY

This application claims priority under 35 U.S.C. § 371 of InternationalApplication No. PCT/JP2004/000774, filed Jan. 28, 2004, which claimspriority of Japanese Patent Application No. 2003-032052, filed Feb. 10,2003.

TECHNICAL FIELD

The present invention relates to a novel method for producing anaromatic diamine derivative; and more particularly to a method forproducing an aromatic diamine derivative which is applied as a chargetransport material of an electrophotographic photoconductor or as anorganic electroluminescent device material.

BACKGROUND ART

Aromatic diamine compounds have been applied as a charge transportmaterial of an electrophotographic photoconductor or as an organicelectroluminescent (EL) device material. Particularly in the case wherean aromatic diamine compound is applied as an organic EL devicematerial, when the device material does not have a high glass transitiontemperature, the resultant organic EL device fails to exhibit heatresistance. Therefore, many attempts have been made to develop anaromatic diamine derivative containing in the molecule thereof a largenumber of aromatic rings (e.g., benzene rings or heterocyclic rings).

However, in general, an aromatic diamine derivative containing in themolecule thereof a large number of aromatic rings exhibits very poorsolubility in a solvent. Such low solubility raises problems, includingprecipitation of diamine molecules in a solvent during the course ofreaction, and limited reaction yield. For example, the followingreaction:

is difficult to progress, because of the presence of a large number ofintramolecular aromatic rings, which cause the raw materials andreaction intermediates to exhibit low solubility.

An aromatic diamine derivative is known to be produced through areaction pathway applying a raw material such as α-naphthylamine,β-naphthylamine, 4-aminodiphenyl, or benzidine, which compounds areknown to exhibit mutagenicity. Production of these compounds, which aredesignated “specified chemical substances,” is prohibited in Japan, andtherefore demand has arisen for a production method which does not applysuch a compound as a raw material or an intermediate.

For example, International Application PCT/JP02/02132 describes, as anexample of such a production method, a method for producing an aromaticamine by reacting an aromatic amine having an arylalkyl group (e.g., abenzyl group) with an aromatic halide, without using a raw material orintermediate which may exhibit mutagenicity as described above.

However, difficulty is encountered in determining conditions for theaforementioned reaction, since the reaction requires a reductionreaction (e.g., hydrogenation) upon elimination of an arylalkyl group,which often causes reduction of an aromatic ring (i.e., a sidereaction).

DISCLOSURE OF THE INVENTION

In order to solve the above-described problems, an object of the presentinvention is to provide a method for producing an aromatic diaminederivative which is useful as a charge transport material of anelectrophotographic photoconductor or as an organic EL device material,and which can be produced at high yield in an efficient manner.

In order to achieve the aforementioned object, the present inventorshave conducted extensive studies, and as a result have found that whenan aromatic amide having a specific structure is reacted with anaromatic halide having a specific structure, an aromatic diaminederivative can be produced at high yield in an efficient manner. Thepresent invention has been accomplished on the basis of this finding.

Accordingly, the present invention provides a method for producing anaromatic diamine derivative represented by the following formula (3),which method comprises reacting an aromatic amide represented by thefollowing formula (1) with an aromatic halide represented by thefollowing formula (2):

(wherein Ar represents a substituted or unsubstituted aryl group having6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroarylgroup having 5 to 30 ring carbon atoms; each of Ar¹ and Ar² represents asubstituted or unsubstituted aryl group having 6 to 30 ring carbonatoms, or a substituted or unsubstituted heteroaryl group having 5 to 30ring carbon atoms; Ar³ represents a substituted or unsubstituted arylenegroup having 6 to 30 ring carbon atoms, or a substituted orunsubstituted heteroarylene group having 5 to 30 ring carbon atoms; andX represents a halogen atom).

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will next be described in detail.

In the present invention, Ar represents a substituted or unsubstitutedaryl group having 6 to 30 ring carbon atoms, or a substituted orunsubstituted heteroaryl group having 5 to 30 ring carbon atoms.Examples of the aryl group include a phenyl group, a biphenylyl group, aterphenylyl group, a naphthyl group, an anthranyl group, a phenanthrylgroup, a pyrenyl group, a chrysenyl group, and a fluoranthenyl group.Examples of the heteroaryl group include a pyrrolyl group, a furanylgroup, a thiophenyl group, a triazole group, an oxadiazole group, apyridyl group, and a pyrimidyl group. Of these, a phenyl group, abiphenylyl group, and a naphthyl group are particularly preferred.

In the present invention, each of Ar¹ and Ar² represents a substitutedor unsubstituted aryl group having 6 to 30 ring carbon atoms, or asubstituted or unsubstituted heteroaryl group having 5 to 30 ring carbonatoms. Examples of the aryl group include a phenyl group, a biphenylylgroup, a terphenylyl group, a naphthyl group, an anthranyl group, aphenanthryl group, a pyrenyl group, a chrysenyl group, and afluoranthenyl group. Examples of the heteroaryl group include a pyrrolylgroup, a furanyl group, a thiophenyl group, a triazolyl group, anoxadiazolyl group, a pyridyl group, and a pyrimidyl group. Of these, aphenyl group, a biphenylyl group, and a naphthyl group are particularlypreferred.

In the present invention, Ar³ represents a substituted or unsubstitutedarylene group having 6 to 30 ring carbon atoms, or a substituted orunsubstituted heteroarylene group having 5 to 30 ring carbon atoms.Examples of the arylene group include a phenylene group, a biphenylenegroup, a terphenylene group, a naphthylene group, an anthranylene group,a phenanthrylene group, a pyrenylene group, a chrysenylene group, and afluoranthenylene group. Examples of the heteroarylene group include apyrrolylene group, a furanylene group, a thiophenylene group, atriazolene group, an oxadiazolene group, a pyridylene group, and apyrimidylene group. Of these, a phenylene group, a biphenylene group,and a naphthylene group are particularly preferred.

Examples of substituent(s) present in Ar and Ar¹ to Ar³ include an arylgroup having 5 to 30 ring carbon atoms, a C1-C12 alkyl or alkoxy group,and an amino group substituted by an aryl group having 5 to 30 ringcarbon atoms.

Examples of the C1-C12 alkyl group include a methyl group, an ethylgroup, an n-propyl group, an i-propyl group, an n-butyl group, ans-butyl group, a t-butyl group, an n-pentyl group, a cyclopentyl group,an n-hexyl group, a cyclohexyl group, and an adamantyl group.

Examples of the C1-C12 alkoxy group include a methoxy group, an ethoxygroup, an n-propyloxy group, an i-propyloxy group, an n-butyloxy group,an s-butyloxy group, a t-butyloxy group, an n-pentyloxy group, acyclopentyloxy group, an n-hexyloxy group, a cyclohexyloxy group, and anadamantyloxy group.

The number of substituent(s) present in each of Ar¹ to Ar³ is preferably0 to 4.

In the present invention, X represents a halogen atom. Examples of thehalogen atom include iodine, bromine, chlorine, and fluorine, withiodine and bromine being particularly preferred.

The production method of the present invention is useful for the casewhere the total number of a benzene ring(s) and/or a heterocyclicring(s) contained in an aromatic diamine derivative represented byformula (3) is 8 or more, particularly for the case where the totalnumber is 10 or more.

In the production method of the present invention, preferably, anaromatic amide represented by formula (1) is reacted with an aromatichalide represented by formula (2) in the presence of a catalyst formedof a transition metal compound.

Examples of the transition metal include Mn, Fe, Co, Ni, Cu, Pd, Mo, Rh,Ru, V, Cr, Pt, Ir, and Zn. Among these, Ni, Pd, Pt, Zn, and Cu arepreferred, with Cu being more preferred.

Examples of the form of the transition metal compound include finepowder of the transition metal, a halide of the transition metal, anoxide of the transition metal, and a chalcogenide compound of thetransition metal, with a halide of the transition metal being preferred.Examples of the halide include a fluoride, a chloride, a bromide, and aniodide, with a bromide and an iodide being particularly preferred. Azero-valent or monovalent transition metal compound is preferablyapplied.

The amount of the catalyst to be added is generally 0.01 to 1equivalent, preferably 0.1 to 0.5 equivalents, with respect to theaforementioned aromatic halide.

Preferably, reaction between the aromatic amide represented by formula(1) and the aromatic halide represented by formula (2) is carried out inthe presence of a base. The base to be applied is preferably a hydroxideor salt of an alkali metal or alkaline earth metal. Among suchhydroxides and salts, a hydroxide, a carbonate, a hydrogencarbonate, andan acetate are preferred, with a hydroxide, which is a strong base,being more preferred.

The amount of the base to be added is generally 2 to 5 equivalents,preferably 2 to 3 equivalents, with respect to the aforementionedaromatic halide.

The reaction solvent applied during the course of reaction between thearomatic amide represented by formula (1) and the aromatic haliderepresented by formula (2) is preferably a hydrocarbon compound, sincethis reaction requires high-temperature heating in the presence of astrong base. Particularly, a solvent having a high boiling point ispreferably applied. Examples of the solvent which may be applied includexylene, decalin, dioxane, dimethylformamide (DMF), and dimethylsulfoxide (DMSO), with xylene and decalin being preferred.

Before being applied, such a solvent is preferably subjected todehydration or inert gas replacement. Dehydration or inert gasreplacement of the solvent can be performed by means of a techniquewhich is generally applied for organic synthesis. For example, adesiccant such as calcium chloride may be added to the solvent, or thesolvent may be subjected to distillation in the presence of calciumhydride or metallic sodium under a stream of, for example, nitrogen orargon.

In the present invention, the temperature of the above-describedreaction is generally room temperature to 150° C., preferably 100 to150° C. The reaction time is 1 to 48 hours, preferably 6 to 18 hours.The reaction process (including preparation of a catalyst) is preferablycarried out in an inert gas atmosphere.

Examples of the aromatic amide represented by formula (1), which isapplied in the production method of the present invention, includeN,N-di-(4-biphenylyl)benzamide, N-(1-naphthyl)-N-phenylbenzamide,N-(2-naphthyl)-N-phenylbenzamide, andN-(1-naphthyl)-N-(4-biphenylyl)benzamide.

Examples of the aromatic halide represented by formula (2), which isapplied in the production method of the present invention, include4,4′-diiodobiphenyl, 1,4-diiodobenzene, 4,4″-diiodo-p-terphenyl,4,4′-dibromobiphenyl, 1,4-dibromobenzene, and 4,4″-dibromo-p-terphenyl.

Examples of the aromatic diamine derivative represented by formula (3),which is produced through the production method of the presentinvention, include N,N,N′,N′-tetra(4-biphenylyl)benzidine andN,N′-di(1-naphthyl)-N,N′-diphenyl-4,4′-benzidine.

The aromatic diamine derivative produced through the production methodof the present invention is useful as a charge transport material of anelectrophotographic photoconductor or as an organic EL device material.

The present invention will next be described in more detail by way ofExamples, which should not be construed as limiting the inventionthereto.

EXAMPLE 1 Production of N,N,N′,N′-tetra(4-biphenylyl) benzidine)

(1) Synthesis of N,N-di-(4-biphenylyl)benzamide

4-Bromobiphenyl (product of Tokyo Kasei Kogyo Co., Ltd.) (10.0 g),benzamide (product of Tokyo Kasei Kogyo Co., Ltd.) (2.31 g), cuprousiodide (product of Kanto Kagaku) (0.36 g), and anhydrous potassiumcarbonate (product of Kanto Kagaku) (5.8 g) were placed in a 100-mLthree-neck flask. Subsequently, a stirrer piece was placed in the flask,a rubber cap (septum) was provided on each of the side necks of theflask, and a spiral reflux condenser was provided on the center neck. Athree-way stop-cock and a balloon containing argon gas were provided onthe reflux condenser. The atmosphere in the reaction system was replacedby the argon gas contained in the balloon by use of a vacuum pump (thisprocedure was performed three times).

Subsequently, diethylbenzene (50 mL) was added through the rubber septumby use of a syringe, the flask was placed in an oil bath, and theresultant mixture was gradually heated to 200° C. under stirring. Sixhours later, the flask was removed from the oil bath, whereby thereaction was completed. Thereafter, the flask was allowed to stand in anargon atmosphere for 12 hours.

The resultant reaction mixture was transferred to a separatory funnel,and dichloromethane (100 mL) was added to the mixture, to therebydissolve the precipitate in the mixture. After the mixture was washedwith saturated brine (60 mL), the resultant organic layer was dried overanhydrous potassium carbonate. The potassium carbonate was separatedthrough filtration, and the solvent of the resultant organic layer wasremoved through evaporation. Toluene (200 mL) and ethanol (40 mL) wereadded to the resultant residue, and the resultant mixture was heated to80° C., with a drying tube being used, to thereby completely dissolvethe residue in the mixture. Thereafter, the mixture was allowed to standfor 12 hours, and was gradually cooled to room temperature forrecrystallization.

The thus-precipitated crystals were separated through filtration, andthen dried under vacuum at 60° C., to thereby yield 7.22 g ofN,N-di-(4-biphenylyl)benzamide.

(2) Synthesis of N,N,N′,N′-tetra(4-biphenylyl)benzidine

The N,N-di-(4-biphenylyl)benzamide obtained above in (1) (1.00 g),4,4′-diiodobiphenyl (product of Wako Pure Chemical Industries, Ltd.)(0.45 g), cuprous iodide (0.021 g), and potassium hydroxide (0.51 g)were placed in a 50-mL two-neck flask. Subsequently, a rubber cap(septum) was provided on the side neck, and a spiral reflux condenserwas provided on the center neck. A three-way stop-cock and a ballooncontaining argon gas were provided on the reflux condenser. Theatmosphere in the reaction system was replaced by the argon gascontained in the balloon by use of a vacuum pump (this procedure wasperformed three times).

Subsequently, xylene (20 mL) was added through the rubber septum by useof a syringe, the flask was placed in an oil bath, and the resultantmixture was gradually heated to 140° C. under stirring. After themixture was stirred at 140° C. for six hours, the flask was removed fromthe oil bath, and was allowed to stand at room temperature for 12 hours.

The thus-precipitated product was completely dissolved indichloromethane (50 mL), and the resultant solution was transferred to aseparatory funnel. After the solution was washed with saturated brine(50 mL), the thus-separated organic layer was dried over anhydrouspotassium carbonate. After filtration of the organic layer, the solventwas removed through evaporation, and toluene (150 mL) and ethanol (50mL) were added to the resultant residue. The resultant mixture washeated to 80° C., with a drying tube being used, to thereby dissolve theprecipitate in the mixture, followed by gradual cooling to roomtemperature. Subsequently, the resultant precipitate was separatedthrough filtration, and washed with a small amount of toluene andethanol. Thereafter, the precipitate was dried by use of a vacuum dryerat 60° C. for three hours, to thereby yield 0.72 g ofN,N,N′,N′-tetra(4-biphenylyl)benzidine.

The thus-obtained N,N,N′,N′-tetra(4-iphenylyl)benzidine was subjected tomeasurement in terms of NMR (nuclear magnetic resonance spectrometry),FD-MS (field desorption mass spectrometry), and HPLC (high-performanceliquid chromatography). The measurement results are as follows.

NMR: δ 90 MHz 7.1-7.8 (44H, m) FD-MS: 792, 396 HPLC: chemical purity of99.6% or more

The overall reaction yield was found to be 73%.

COMPARATIVE EXAMPLE 1 Production ofN,N,N′,N′-tetra(4-biphenylyl)benzidine: production through a pathwaydifferent from that of Example 1

(1) Synthesis of N,N-di-(4-biphenylyl)-benzylamine

4-Bromobiphenyl (product of Tokyo Kasei Kogyo Co., Ltd.) (10.0 g),sodium t-butoxide (product of Wako Pure Chemical Industries, Ltd.) (4.32g), and palladium acetate (product of Wako Pure Chemical Industries,Ltd.) (42 mg) were placed in a 100-mL three-neck flask. Subsequently, astirrer piece was placed in the flask, a rubber cap (septum) wasprovided on each of the side necks of the flask, and a spiral refluxcondenser was provided on the center neck. A three-way stop-cock and aballoon, containing argon gas were provided on the reflux condenser. Theatmosphere in the reaction system was replaced by the argon gascontained in the balloon by use of a vacuum pump (this procedure wasperformed three times).

Subsequently, dehydrated toluene (product of Wako Pure ChemicalIndustries, Ltd.) (60 mL), benzylamine (product of Tokyo Kasei KogyoCo., Ltd.) (2.04 mL), and tris-t-butylphosphine (product of Aldrich,2.22 mol/L toluene solution) (169 μL) were added through the rubberseptum by use of a syringe, and the resultant mixture was stirred atroom temperature for five minutes.

Subsequently, the flask was placed in an oil bath, and the resultantmixture was gradually heated to 120° C. under stirring. Seven hourslater, the flask was removed from the oil bath, whereby the reaction wascompleted. Thereafter, the flask was allowed to stand in an argonatmosphere for 12 hours.

The resultant reaction mixture was transferred to a separatory funnel,and dichloromethane (300 mL) was added to the mixture, to therebydissolve the precipitate in the mixture. After the mixture was washedwith saturated brine (60 mL), the resultant organic layer was dried overanhydrous potassium carbonate. The potassium carbonate was separatedthrough filtration, and the solvent of the resultant organic layer wasremoved through evaporation. Toluene (200 mL) and ethanol (40 mL) wereadded to the resultant residue, and the resultant mixture was heated to80° C., with a drying tube being used, to thereby completely dissolvethe residue in the mixture. Thereafter, the mixture was allowed to standfor 12 hours, and was gradually cooled to room temperature forrecrystallization.

The thus-precipitated crystals were separated through filtration, andthen dried under vacuum at 60° C., to thereby yield 6.73 g ofN,N-di-(4-biphenylyl)-benzylamine.

(2) Synthesis of di-4-biphenylylamine

The N,N-di-(4-biphenylyl)-benzylamine obtained above in (1) (1.35 g) andpalladium-activated carbon (product of Wako Pure Chemical Industries,Ltd., palladium content: 10 wt. %) (135 mg) were placed in a 300-mLone-neck flask, and chloroform (100 mL) and ethanol (20 mL) were addedto the flask, followed by dissolution of these materials in thesolvents.

Subsequently, a stirrer piece was placed in the flask, and then athree-way stop-cock equipped with a balloon filled with hydrogen gas (2L) was provided on the flask. The atmosphere in the flask was replacedby the hydrogen gas by use of a vacuum pump (this procedure wasperformed 10 times). The balloon was filled with fresh hydrogen gas soas to compensate for the above-consumed hydrogen gas. After the hydrogengas volume was returned to 2 L, the solution contained in the flask wasvigorously stirred at room temperature for 30 hours. Thereafter,dichloromethane (100 mL) was added to the solution, and the catalyst wasseparated through filtration.

Subsequently, the resultant solution was transferred to a separatoryfunnel, and the solution was washed with a saturated aqueous solution ofsodium hydrogencarbonate (50 mL). Thereafter, the resultant organiclayer was separated, and dried over anhydrous potassium carbonate. Afterfiltration of the organic layer, the solvent was removed throughevaporation, and toluene (50 mL) was added to the resultant residue forrecrystallization. The thus-precipitated crystals were separated throughfiltration, and then dried under vacuum at 50° C., to thereby yield 0.99g of di-4-biphenylylamine.

(3) Synthesis of N,N,N′,N′-tetra(4-biphenylyl)benzidine

The di-4-biphenylylamine obtained above in (2) (0.500 g),4,4′-dibromobiphenyl (product of Tokyo Kasei Kogyo Co., Ltd.) (0.231 g),palladium acetate (0.0034 g), and sodium t-butoxide (0.157 g) wereplaced in a 50-mL two-neck flask. Subsequently, a rubber cap (septum)was provided on the side neck, and a spiral reflux condenser wasprovided on the center neck. A three-way stop-cock and a ballooncontaining argon gas were provided on the reflux condenser. Theatmosphere in the reaction system was replaced by the argon gascontained in the balloon by use of a vacuum pump (this procedure wasperformed three times).

Subsequently, dehydrated toluene (10 mL) and tris-t-butylphosphine(product of Aldrich, 2.22 mol/L toluene solution) (13.4 μL) were addedthrough the rubber septum by use of a syringe, the flask was placed inan oil bath, and the resultant mixture was gradually heated to 115° C.under stirring. After the mixture was stirred at 115° C. for six hours,the flask was removed from the oil bath, and was allowed to stand atroom temperature for 12 hours.

The thus-precipitated product was completely dissolved indichloromethane (500 mL), and the resultant solution was transferred toa separatory funnel. After the solution was washed with saturated brine(100 mL), the thus-separated organic layer was dried over anhydrouspotassium carbonate. After filtration of the organic layer, the solventwas removed through evaporation, and toluene (150 mL) and ethanol (50mL) were added to the resultant residue. The resultant mixture washeated to 80° C., with a drying tube being used, to thereby dissolve theprecipitate in the mixture, followed by gradual cooling to roomtemperature. Subsequently, the resultant precipitate was separatedthrough filtration, and washed with a small amount of toluene andethanol. Thereafter, the precipitate was dried by use of a vacuum dryerat 60° C. for three hours, to thereby 0.453 g of yieldN,N,N′,N′-tetra(4-biphenylyl)benzidine.

The thus-obtained N,N,N′,N′-tetra(4-biphenylyl) benzidine was subjectedto measurement in terms of NMR, FD-MS, and HPLC. The measurement resultsare as follows.

NMR: δ 90 MHz 7.1-7.8 (44H, m) FD-MS: 792, 396 HPLC: chemical purity of99.5% or more

The overall reaction yield was found to be 63%.

COMPARATIVE EXAMPLE 2 Production ofN,N,N′,N′-tetra(4-biphenylyl)benzidine: the case where Ar of formula (1)is a methyl group

(1) Synthesis of N,N-di-(4-biphenylyl)acetamide

4-Bromobiphenyl (product of Tokyo Kasei Kogyo Co., Ltd.) (10.0 g),sodium t-butoxide (product of Wako Pure Chemical Industries, Ltd.) (4.32g), and palladium acetate (product of Wako Pure Chemical Industries,Ltd.) (42 mg) were placed in a 100-mL three-neck flask. Subsequently, astirrer piece was placed in the flask, a rubber cap (septum) wasprovided on each of the side necks of the flask, and a spiral refluxcondenser was provided on the center neck. A three-way stop-cock and aballoon containing argon gas were provided on the reflux condenser. Theatmosphere in the reaction system was replaced by the argon gascontained in the balloon by use of a vacuum pump (this procedure wasperformed three times).

Subsequently, dehydrated toluene (product of Wako Pure ChemicalIndustries, Ltd.) (60 mL), acetamide (product of Tokyo Kasei Kogyo Co.,Ltd.) (1.24 g), and tris-t-butylphosphine (product of Aldrich, 2.22mol/L toluene solution) (169 μL) were added through the rubber septum byuse of a syringe, and the resultant mixture was stirred at roomtemperature for five minutes.

Subsequently, the flask was placed in an oil bath, and the resultantmixture was gradually heated to 120° C. under stirring. Seven hourslater, the flask was removed from the oil bath, whereby the reaction wascompleted. Thereafter, the flask was allowed to stand in an argonatmosphere for 12 hours.

The resultant reaction mixture was transferred to a separatory funnel,and dichloromethane (300 mL) was added to the mixture, to therebydissolve the precipitate in the mixture. After the mixture was washedwith saturated brine (60 mL), the resultant organic layer was dried overanhydrous potassium carbonate. The potassium carbonate was separatedthrough filtration, and the solvent of the resultant organic layer wasremoved through evaporation. Toluene (200 mL) and ethanol (40 mL) wereadded to the resultant residue, and the resultant mixture was heated to80° C., with a drying tube being used, to thereby completely dissolvethe residue in the mixture. Thereafter, the mixture was allowed to standfor 12 hours, and was gradually cooled to room temperature forrecrystallization.

The thus-precipitated crystals were separated through filtration, andthen dried under vacuum at 60° C., to thereby yield 0.91 g ofN,N-di-(4-biphenylyl)acetamide.

(2) Synthesis of N,N,N′,N′-tetra(4-biphenylyl)benzidine

The procedure of Example 1 (2) was repeated, except that theN,N-di-(4-biphenylyl)benzamide (1.00 g) was replaced by theN,N-di-(4-biphenylyl)acetamide obtained above in (1) (0.85 g), tothereby yield 0.38 g of N,N,N′,N′-tetra(4-biphenylyl)benzidine.

The thus-obtained N,N,N′,N′-tetra(4-biphenylyl)benzidine was subjectedto measurement in terms of NMR, FD-MS, and HPLC. The measurement resultsare as follows.

NMR: δ 90 MHz 7.1-7.8 (44H, m) FD-MS: 792, 396 HPLC: chemical purity of99.3% or more

The overall reaction yield was found to be 5%.

INDUSTRIAL APPLICABILITY

As described above in detail, the method of the present invention canproduce, at high yield in an efficient manner, an aromatic diaminederivative which is useful as a charge transport material of anelectrophotographic photoconductor or as an organic electroluminescentdevice material.

1. A method for producing an aromatic diamine derivative represented byformula (3), which method comprises reacting an aromatic amiderepresented by formula (1) with an aromatic halide represented byformula (2):

wherein Ar represents a substituted or unsubstituted aryl group having 6to 30 ring carbon atoms, or a substituted or unsubstituted heteroarylgroup having 5 to 30 ring carbon atoms; each of Ar¹ and Ar² represents asubstituted or unsubstituted aryl group having 6 to 30 ring carbonatoms, or a substituted or unsubstituted heteroaryl group having 5 to 30ring carbon atoms; Ar³ represents a substituted or unsubstituted arylenegroup having 6 to 30 ring carbon atoms, or a substituted orunsubstituted heteroarylene group having 5 to 30 ring carbon atoms; andX represents a halogen atom.
 2. A method for producing an aromaticdiamine derivative as described in claim 1, wherein the aromatic diaminederivative represented by formula (3) contains a benzene ring(s) and/ora heterocyclic ring(s) in the total number of 8 or more.
 3. A method forproducing an aromatic diamine derivative as described in claim 1,wherein the aromatic amide represented by formula (1) is reacted with anaromatic halide represented by formula (2) in the presence of a catalystcomposed of a transition metal compound.
 4. A method for producing anaromatic diamine derivative as described in claim 3, wherein thetransition metal compound is a copper compound.
 5. A for producing anaromatic diamine derivative as described in claim 1, wherein thearomatic amide represented by formula (1) is reacted with an aromatichalide represented by formula (2) in the presence of a base composed ofa hydroxide.
 6. A method for producing an aromatic diamine derivative asdescribed in claim 5, wherein the hydroxide is an alkali metal hydroxideand/or an alkaline earth metal hydroxide.
 7. A method for producing anaromatic diamine derivative as described in claim 1, wherein reaction isperformed in a hydrocarbon compound serving as a reaction solvent.
 8. Amethod for producing an aromatic diamine derivative as described inclaim 1, wherein the aromatic diamine compound serves as a chargetransport material for use in an electrophotographic photoconductor. 9.A method for producing an aromatic diamine derivative as described inclaim 1, wherein the aromatic diamine compound serves as an organicelectroluminescent device material.